Dust cover for a lock mechanism



April 12, 1960 J. A. MAHRLEY m m ml 1 w i w w R P T 2,932,186 DUST COVER FOR A LOCK MECHANISM John A. Mahrley, White Plains, N.Y., assignor to The Yale & Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Application November 8, 1956, Serial No. 621,161 13 Claims. 01. -455 This invention relates to locks, and more particularly to a lock of the type having a key way that must be guarded against the entry of moisture and dirt.

Those skilled in the art appreciate fully that the prob-' lem of closing a keyhole to prevent the entry of moisture and dirt is one that has confronted the art for many years. There are numerous patents showing various types of means for sealing a keyhole, but so far as I know, no prior art construction has been completely successful. This is due to the fact that it is extremely difficult to seal a keyhole and yet to allow for the free admission of a key, particularly if but one hand is to be used to insert the key into the lock. Locks used on automobiles are particularly difficult to seal because of wind conditions, and yet such locks must permit easy entry of the. operating key. I The lock of my invention contributes a novel form ofseal for the keyhole that will be very effective, but that will nevertheless permit easy entry of the key. Thus, as a feature of my invention I use a pin that is mounted for movement into a position sealing the keyhole, the pin being readily movable out of position by the key. As a more particular feature of the invention, the pin is cylindrical and therefore readily adjusts itself to a surface specially formed at the rear of the head of the key plug so as to seal the keyhole, the keyhole naturally being formed in the head.

As a further feature of my invention, the sealing pin is adapted for bodily movement toward itsposition sealing the keyhole, and in a diagonal direction away from that sealing position upon being pushed by the key. The pin movement is contributed through a spring, but to insure the diagonal movement I prefer to utilize guide surfaces formed on the key plug or head for guiding the pin during its movement by the spring.

As a further feature of my invention, the head of the key plug in my preferred construction is a separate member that is applied and retained thereon by the cylinder in which the key plug rotates. As a part of that construc-' tion, I prefer to equip the cylinder with a conventional scalp that lies against the key plug'thead. It is a further featureof my invention that the head of the key plug is preferably formed of some self-lubricating material such as powdered metal or a plastic, such as polyethylene or vinyl.

I have thus outlined rather broadly the more importantfeatures of my invention in order that the detailed description thereof that follows may be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention.

. Referring now to the drawing:

Fig. 1 shows mounted on a door a lock that utilizes my nov l d st eve nited States aten-tO Fig. 2 is a cross section taken on the line 22 in Fig. 1.

Fig. 3 is similar to Fig. 2 but shows my dust cover with a key inserted in the key Way of the lock.

' Fig. 4 is a view taken on the line 44 in Fig. 2.

For the purpose of describing my invention, I show in the drawing a rather usual lock cylinder 10 in which is a rotating key plug 11 having a key way 12. The key way 12 is adapted to accept a key K, shown inFig. 3, for actuating lock tumblers in the lock, as will be understood by those skilled in the art. In my invention, I utilize on the key plug 11 a head 13, well shown in Fig. 2, that has a keyhole 14 and that is so arranged as to leave a space 15 between the head and the front end of the key plug. In the construction that I have chosen to illustrate, a portion 16 of the space 15 actually extends into the key plug 11, but the particular manner in which space 15 is formed is not important to an understanding of my invention. The head 13 has further features that I shall describe, but at this point it is merely necessary to know that there is a space immediately behind the head 13.

I further utilize in 'my invention a sealing member 17 that I prefer to 'make'in the form of a round pin, that member or pin 17 being somewhat wider than the keyhole 14 and adapted to move bodily in the space 15 relatively to the keyhole. Together with the sealing member or pin 17, I utilize a spring 18 that presses the pin'in the space 15 toward the rear surface of the head 13. The spring 18 in the preferred form of my invention is formed with coil portions 19 that are mounted on the key plug 11, and also with end portions 20 that engage the front of the plug and further portions 21 acting against end parts 22 on pin 17. The arrangement is such that the spring 18 presses the pin 17 bodily in a diagonal direction toward the keyhole 14. Also, the spring portions 20 by their position are out of aligned relation to the'key way 12 and keyhole 14 and do not obstruct the key way.

To coact with the pin 17, I form the head 13 around keyhole 14 with sealing surfaces 23, 24 as will be understood from Figs. 2 and 3. Those surfaces 23, 24 are shaped to coact with the surface of the pin 17 whereby to locate the pin and to form with the pin an elfective seal for the keyhole. Further, I prefer to utilize for the head 13 a yielding material, such as a polyethylene plastic. I have found that such a material, While relatively firm, will'neverthless yield so that the surfaces 23, 24 on the head will conform even more precisely to the pin 17.

Moreover, a polyethylene plastic has lubricating properties whereby the pin 17 will move easily to-actual sealing position, without friction that might prevent a perfectseal.

' Itwill be observed'that the portions 21 on spring 18, while moving the pin 17 towards sealing position, will nevertheless yield when the key K is inserted into the keyhole 14, so that the pin 17 will move rearwardly and alsoto one side to enable the key K to move into the key way 12, all as shown in Fig. 3. I do prefer, however, to construct the key plug 11 with guide surfaces 25 whereby the pin 17 when moved by the key K will be positively guided in a diagonal direction. Further, I prefer to construct the key plug head 13 with a diagonal surface 26 that will guide the pin 17 against the sealing surfaces 23, 24, when spring 18 moves the pin.. It will thus be seen that my invention enables me to achieve: perfect sealing of the keyhole 14, but with the key K nevertheless adapted to move very easily past the seal and into the key way 12. This I do through the utilization of the sealing member or pin 17 that moves bodily in the space 15 on the key plug, that pin'moving toward andaway from the head of the key plug, and also into and out of aligned relation to the key way. I shall now call attention to the fact that my invention enables me to utilize the spring pressure of "the sealing pin 17 in an, extremelynovel way to. seal; the;

3 head 13 on the key plug relatively to the lock cylinder 10. Thus, it will first be observed that the front of the key plug head 13 will accept the spring pressure of pin 17 when that .pin is in sealing position, the 1 spring pressure thereby ,pressing the head in an outward direction. Further, I equip [the cylinder with aErather usual circular part or scalp 27, well shown in Fig. 2, that overlies the front of the head 13 with its edge 28 in position to contact the'head. To coact with-the edge 28, I prefer to form. the front of the head 13 with an inclined surface portion 29, but that inclined formation is not actually necessary. The arrangement is such that the head 13, by yielding under the pressure applied by the sealing pin 17 will be pressed against the scalp 27 whereby to form an extremely effective seal between the key plug 11 and lock cylinder 10. Of course, it is conceivable that the key plug head 13 may be formed of rigid material, with the head 13 sealed relatively to scalp 27 through a slight movement of the head or key plug, and therefore I do not wish to be limited to yielding material.

Since in my preferred construction I do utilize yielding material for the head 13, I am able to form the head with a rim portion 30 that is adapted to be snapped into a peripheral groove 31 on the key plug 11 whereby to assemble the head to the plug. I contemplate forming the rim portion 30 to lie somewhat loosely in the groove 31, as may be seen in Fig. 2, so that the head 13 can have a slight movement in an axial direction relatively to key plug 11. I then form the head 13 with lugs 32 that will be positioned in notches in the end of key plug 11 so that the head and plug will rotate integrally, with the keyhole 14 and key way 12 held in aligned relation to one another.

I believe that those skilled in the art will ,now understand that I have conceived an extremely novel dust cover that has very considerable advantages over the prior art. Through my invention, I contribute a seal that will absolutely prevent the entry of dust or moisture into a keyhole, and that will remain effective despite wind or other adverse conditions. While contrib uting an exceedingly effective seal, my novel dust cover nevertheless does not substantially oppose the insertion of a key, and actually enables the key to be inserted very easily. Further, my construction can be utilized not only to seal the keyhole, but also to seal the key plug, thus sealing the entire front end of the lock. These things I accomplish through means that actually are rather simple, with relatively few parts. therefore, that the valueof my invention-v will be very readily appreciated.

I now claim:

1. In a lock of the class described, a key plug having a key way and a front head formed with a keyhole through which a key maybe inserted into said key way, there being a space immediately behind the head of the key plug, a pin in said space adapted to lie against the rear surface of the head, said head being formed around the keyhole for coaction with the pin and to locate the pin so that the pin seals said keyhole, and a spring in said space acting on the opposed end portions of said pin to press the pin against the said rear surface of the head.

2. In alocko'fthe class described, a key plug having a key way and a front head "formed with a keyhole through which a key may be inserted into 'said key way, there being a space immediately behind the head of the key plug, a cylindrical pin in said space adapted to lie against the rear surface of the head, saidrear surface being formed "for 'coaction with the pin and to locate the pin so that the pin'seals said keyhole, a spring in said space pressing at the upper and lowerends of said pin to hold the pin'against 'the'said rear surface of the head, and the pressure of said spring acting on said pin in a directiondiagonalpf the key-way whereby I believe, a

a key will move said pin to one side and rearwardly through yielding of the spring as the key enters sa'id keyhole for further movement into the key way.

3. In a lock of the class described, a key plug having a key way and a front head formed with a keyhole through which a key may be inserted into said key way, there being a space immediately behind the head of the key plug, a cylindrical pin in said space having a diameter larger than the width of said keyhole and adapted to lie against the rear'surface of the head} said rear surface being formed for coaction with the pin and to locate the pin so that the pin seals said keyhole, a spring in said space pressing said pin against the said rear surface of the head, and means guiding said pin into movement toward the head in a direction diagonal of the key way whereby a key will move said pin diagonally away from the keyhole and key way through yielding of the spring as the key enters said keyhole.

4. In a lock of the class described, a key plug having a key way into which a key may be inserted, a head on said key plug having a keyhole in aligned relation to the key way, there being a space immediately behind the head of the key 'plug at the front end of the key plug, a pin adapted to move bodily in said space toward and away from the rear surface of the head and also into and out of aligned relation to the key way and keyhole, a spring pressing the pin in said space toward the rear surface of the head, said head formed around the keyhole with surface portions shaped to coact with the surface of said pin, guide means extending diagonally of the key way and on which the pin by its spring pressure moves bodily against said surface portions of the head to seal the keyhole, and said pin moving away from said surface portions and to one side through yielding of said spring when a key enters the keyhole so that the key can move into the key way.

5. In a lock of the class described, .a key plug having a key way into which a key may be inserted, a head on said key plug having a keyhole in aligned relation to .the key way, there being a space immediately behind the head of the key plug at the front end of the key plug, .a pin adapted to move bodily in said space toward and away from the rear surface of the head and also into and out of aligned relation to the key way and keyhole, said head formed around the keyhole with surface portions shaped ,to coact with the surface of said pin, a spring pressing said pin toward the keyhole so that the pin moves bodily against said surface portions of the head to seal the keyhole, said pin moving in said space away from the head of the key plug through yielding of said spring when a key enters the keyhole, and a diagonal guide on which the pin when moving away from the head moves also out of aligned relation to the key way and keyhole whereby .to enable'the key to move into the key way.

6; In a lockof the class described, a key plug having a key way into which a key may be inserted, a head on said key plug having a keyhole in aligned relation to the key way, there being a space immediately behind the head of the key plug at the front end of the key plug, a pin adapted to move bodily in said space toward and away from the rear surface of the head and also into and out of alignedrelation to the key way and keyhole, said head formed around the keyhole with surface portions shaped to coact with the surface of said pin, spring means pressing against each end portion of said pin to move the pin bodily .toward the keyhole, said pin by'its bodily movement acting against said surface portions of the head to seal the keyhole, and said pin moving away from said surface portions and to one' sidethrough yielding of said spring when iakey enters the keyhole so that the key canmove into the key way.

7. In a lock of the class described, a lock cylinder, a key plu'g movable-in saidcylinder and having a key way terminating at the front end of the key plug, a head for said key plug formed from yielding material and having a keyhole therethrough, there being a space immediately behind the said head of the key plug, a pin in said space adapted to lie against the rear surface of the yielding head, said rear surface being formed for coaction with the pin and to locate the pin so that it will seal said keyhole, a spring pressing said pin in said space against the said rear surface of the head, a circular part on the lock cylinder overlying a front portion of the head, and the spring pressure of the pin acting through yielding of the head to press the front of the head against the said part on the cylinder whereby to seal the head relatively to the cylinder.

8. In a lock of the class described, a lock cylinder, a key plug rotating in said cylinder and having a key way terminating at the front end of the key plug into which a key may be inserted, a head for said key plug formed from yielding material and having a keyhole therethrough, a rim on said head snapped into a groove on the key plug to assemble the head to the plug with the rim lying between the plug and cylinder, a circular part on the lock cylinder extending over a portion of the head around the keyhole, and the yielding material of said head lying in contact with said circular part whereby to seal the head relatively to the cylinder. 7

9. In a lock of the class described, a key plug having a key way into which a key may be inserted, a head on said key plug having a keyhole in aligned relation to the key way, there being a space immediately behind the head of the key plug at the front end of the key plug, a 'pin adapted to move bodily in said space toward and away from the rear surface of the head and also into and out of aligned relation to the key way and keyhole, spring means pressing against each end portion of said pin to urge the pin toward the rear surface of the head, said head formed around the keyhole with surface portions shaped to coact with the surface of said pin, guide means extending diagonally toward the rear surface of the head and on which the spring means moves the pin bodily against said surface portions of the head to seal the keyhole, said'pin moving in said space away from the head of the key plug through yielding of the spring: means when a key enters the keyhole, and a part of said diagonal guide means on which the pin when moving away from the head moves also out of aligned relation to the key way and keyhole so that the key can move into the keyway.

10. In a lock of the class described, a key plug having a keyway into which a key may be inserted, a head on said key plug formed of yielding material and having a keyhole in aligned relation to the key way, there being a space immediately behind the head of the key plug at the front end of the key plug, a pin adapted to move bodily in said space toward and away from the rear surface of the head and also into and out of aligned relation to the key way and keyhole, spring means pressing against each end portion of said pin to urge the pin toward the rear surface of the head, said head formed around the keyhole with surface portions shaped to coact with the surface of said pin, guide means extending diagonally on said head toward the keyhole and on which the spring means moves the pin bodily against said surface portions of the head to seal the keyhole through yielding of the material of the head, said pin moving in said space away from the head of the key plug through yielding of the spring means when a key enters the keyhole, and said key plug having a diagonal guide on which the pin when moving away from the head moves also out of aligned relation to the key way and keyhole so that the key can move into the key way.

11. In a lock of the class described, a lock cylinder, a key plug rotating in said cylinder and having a keyway into which a key may be inserted, a head on said key plug formed of yielding material and having a keyhole in aligned relation to the keyway, there being a space immediately behind the head of the key plug at the front end of the key plug, a pin adapted to move bodily in said space toward and away from the rear surface of the head and also into and out of aligned relation to the key way and keyhole, spring means pressing against each end portion of said pin to urge the pin bodily toward the rear surface of the head, said head formed around the keyhole with surface portions shaped to coact with the surface of said pin, guide means extending diagonally toward the keyhole and on which the spring means moves the pin bodily against said surface portions of the yielding head to seal the keyhole, a circular part on the lock cylinder overlying a front portion of the head, the spring pressure of the pin acting through yielding of the head to press the head against said circular part whereby to seal the head relatively to the lock cylinder, the entry of a key into the keyhole effecting movement of said pin away from said head through yielding of the spring means when a key enters the keyhole, and a part of said diagonal guide means on which the pin when moving away from the head moves also out of aligned relation to the key way and keyhole so that the key can move into the key way.

12. In a lock of the class described, a key plug having a key way terminating the front end of the key plug and into which a key may be inserted, a head for said key plug having a keyhole therethrough, there being a space immediately behind said head of the key plug at the front end of the key plug, a pin assembled in said space and having a curved surface portion, said pin adapted to move bodily in said space to lie against the rear surface of the head with said curved surface portion lying in said keyhole, said rear surface of the head being formed for coaction with the pin and to locate said pin through bodily movement of the pin so that the pin seals said keyhole of said head, a spring in said space behind the head pressing said pin to sealing position, and a portion of said spring formed to yield in a direction diagonal of the key way so that a key pressed against said curved surface portion of the pin can move said pin bodily to one side and rearwardly relatively to the keyhole.

13. In a lock of the class described, a lock cylinder, a key plug rotating in said cylinder and having a key way terminating at the front end of the key plug into which a key may be inserted, a head for said key plug formed from yielding material and having a keyhole therethrough, a rim on said head snapped into a groove on the key plug to assemble the head to the plug with the rim lying between the plug and cylinder, and a circular part on the lock cylinder extending around a portion of the head and lying in contact with the yielding material of said head whereby to seal the head relatively to the cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 1,020,208 Laughlin Mar. 12, 1912 1,228,445 Janes June 5, 1917 1,965,942 Jacobi July 10, 1934 2,655,031 Jacobi Oct. 13, 1953 2,690,071 Jacobi Sept. 28, 1954 FOREIGN PATENTS 605,547 Great Britain July 26, 1948 

